Spark-plug.



No. 889,432. PATENTED JUNE 2, 1908. G. J. BLUM. SPARK PLUG. APPLIOATION FILED PEB. 7. 190e.

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unirsi) srArEs .PATENT I OFFICE. f

GEORGE .Tf-BLUM, OF CHICAGO, ILLINOIS, ASSIGNOR TO ARMSTRONG-BLUM MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS,y A CORPORATION OF ILLINOIS.

SPARK-PLUG Specification df Lettersl Patent.

, Patented J'u'nel2, 1908.

Application filed February 7, 1906. Serial N-O. 299,933..

This inventionrelates to the. devices, cornmonly known as spark plugs,pemployed for' firing the charge in the cylinders of explosive engmes.

One of the objects of the invention is. the

roduction of a spark plug; the actionof which shall be certain and not liable .to be? 16 disturbed by reason of the pressure of the gases in the engine cylinder.

Another object is the provision of means for taking up wear of the contacts.

ing arts.

improvements in spark plugs hereinafter set forth.

The embodiment herein shown of the invention comprises a iixed contact, a contact Vcarried upon a .pivoted arm, a spring tend` ing to hold the contacts to ether,fand an electromagnet in circuit l In theaccompanying drawings, Figure 1 is a perspective view of a spark plug embodylng the features of my invention Fig.

2 is a vertical central section through sai 35 plug. Fig. 3,is asimilar sectional view, but taken on 'a plane at right angles to that of Fig.2. Fig. 4 is an enlarged Vdetail view of the shaft for supporting the movable. cone' tion, the body 'portion of the spark plug consists of a spool 1 comprising the stem 2 having a.`T-head 3 formed integral-with its` 45 .upper end and a Tehead 4 at its lowen end. An externally screw --threaded attaching stem 5 is also formed integral withsaid stem .for securing the s ark plug to an engine cylinder.

A meta slit 71l connecting said lopening with the periphery of the disk, is adapted' to lie against the inner side of eachof theT-heads 3 and 4,.said disks .forming the ends of the 5'5 spool 1.# In practice, the disks 6 are placed A further object is theprevention of leakl age of gas through'the bearings of the mov- T e invention also relates. to the further the contacts tact.l Fig. 5 'is a detail view of. a modified' 'c disk 6 preferably of. brass and havinga central Opening 7 anda.

in position byspringing the slitted portion over the stem 2.A The spool 1 supports a coil 8 of magnet Wire, suitably insulated from the heads 3 and 4 by disks 8 preferably of asbestos. The coil 8 is connected at its A@o outer end, .bymeans of a contact plate 9, with a binding post 10, said binding post extending through the T-head 3' and being insulated therefrom by means of .the bushing 11 of lava or other suitable Amaterial-65l The inner end of the coil 8 is attached to a `pin 12A extending vertically through an opening 13 'in the lower T-head 4 and the secur-4 f in stem 5.- The pin 12 is insulated from said T-head an'd securing stem by means of 70 alava bushing 14 iixed on saidrod by means .of nuts. 15. A contact 16, of platinumV or other suitable material, 'is' secured to a `collar 17 upon the lower'end of the in 12,

and is locked in position on said pin y the clamping nut 18. Y. Y

The movable contact 31.9 is carried at the lower 'end lof a finger '20, the u `pei-'end of which finger is fixed to a rock s aft 21 .su-pported vin openings 22 in the lower T-head 89 4, the securing stem 5 and T-head 4 being chambered at 23 for the reception of said iinger. The outer ends of the 'shaft 21 have vfixed thereto the twoarrns 24 of an. armature 25 extending across-the T-heads 3 and 4 and 3 5 adapted" to be attracted by said-T-heads when the latter are magnetized. lA leaf spring' 26 tends to move the armature 25 away from the T-heads 3- and 4, saidspring l being fixedA at one end to the vouter side of 90 said. armature and its other end'having a screw-thread engagement with a set screw 27v extending through an opening 28gin said armature and-"bearing against one end of the T-head 3. y The rock'shaft21comprises two screws 29 threaded into the openings. 22 the'T--head 4'. The screws 29 are, axially .perforated to receivea bolt 30;. The; upper y endof thenger`20-*als`o isI')erforated-I or the receptionof 1.00

said bolt, andsaid.f inger.i s clampedfbetween x the inner end of the Iscrews 29.]oy turning said screws .hy means ofjtheir square vheads 31. The arms 24 of the armature 25- have' openings therein through'.which the bolt 30 .105

passes, and saidV arms are clamped tightlyto v the ends of the screws 29.by drawingup said bolt, which'boltengages a nut 32 brazed or otherwisesecuredto one of` the/arms 24. In assembling the lmovable parts, the screws 29 1,10

- mally holds the contacts .the openings 22, .preventing their rotating freely insaid openings. This pressure of the screws uponthe threads in the openings 22 is relieved and the parts firmly-clamped together by drawing up the bolt 30 until the screws 29 yturn freely in said op'enings'. The screws 29, however, iit their screw-threaded openings 22 closely .enough to prevent any escape of gas through said openings.

In Fig. 5 is shown an alternative construction of the shaft. 21. It comprises two screws 38 the inner threaded end s'of which are'adapted'to enter the tubular internallyof the finger 20a. The screws 3 3 are caused to grip thethreads within the `hub 34, in order to fix` the finger 20a rigidly boites).

In use, the spark plug is attached to 'an' enlinder by means of the securing stem 5, and said plug included in an electric circult by connecting one of the battery wires to the .binding post 10.- The spring 26 nor- 16 and 19 to ether, thus closing the circuit. A current owing through the coil 8 sets .up

The contact 19V the armature 25',

the contacts, breaking ing the formation of a spark between said `ergizes the electromagnet and allows the spring 26 to Withdraw the armature, the pivotal movement ofthe armature again bringing the contacts 'together and thereby 'closing the circuit.

Vtude of vibration of the armature 25 is autothe screw 27. When the wear uponI the contacts 1.6 and 19 becomes so great asjto make 19 with reference to the range of movement of the armature more than is desirable, the position of the contact said armature may be changed by slackening the bolt 30an`d the screws 29 adjusting the position of the finger 20, and tightening said bolt andscre'ws'.

It'is evident that various changes may be made Nin the embodiment herein shown withoutdeparting-from the spirit and scope of my invention, therefore no undue' limitation should be understood from the foregoing 'detailed description;

4claimas my invention:

1. In a spark plug, in combination, an

i electromagnet; 'a fixed contact; a movable contact; a

shaft-members.

upon its shaft, by drawing up the.

i tween the sections'of extending magnetism in the -heads '3 and 4, whereupon said T -heads attract thearmature 25,.

lbeing fixed `with relation to the movement of said armature separates.

-the circuit and caus- .lying in said'openings,

-said screws beingv axiall :finger for carrying saidA movable said finger is clamped; andan y 2. In a spark plug,.in combination, an

lelectromagnet; a fixed contactga movablel contact; a finger for carrying said movable' contact; a shaft to` which said finger is 'clamped,' an armature provided with two supporting arms and aclamping bolt 'extending through said` arms and said shaft.

3. In a sparkplug; in combination, an electromagnet;

prisan armature; and means'for clamping said armature to said 4. In avspark plug, in combination, an electromagnet; a fixed contact, a finger carrying a second contact; a sectional shaft bel l which said iingeris and a clamping bolt shaft and engaging clamped; an armature;

through said said armature.

f5. In a spark plug, in combination, a body portion having' two alined screw-threaded openings ftherein;` a shaft comprising two screws lyingv in said openings a finger adapted to be clamped between the ends of said screws and carrying a contact; means for longitudinally compressing said screws; a

. stationary contact;A an electromagnet in circuit with said contacts; and an armature fixed with relation to said shaft.` f 6. The combination with a bodyfportio'n having two alined `screw-threaded openings therein, of a shaft comprising two screws lying in said openings; a member adapted to be clamped between the ends of said screws and means for llongitudinally compressing l said screws.A i' As the contacts '1.6 and 19 wear the ampliafixed.' contact; a 'finger .carrying a second contact; ashaft com 'ing two members -adapted to clamp said' `finger between them,

7. The combination with a body portion having two alined screw-threaded openings therein, of a shaft comprising two Ascrews lying in said openings 3 a member adapted to beclamped between the ends of said screws, said screws being axially perforated,

and means comprising a bolt extendingV .through said' perforations for compressing said screws.

'8. The combination with abody portion having two alined screw-threaded openings thereinof a shaft comprisingl two screws said screws having angular heads upon their ou'ter ends 5 a member adapted to be clamped betweenthe inner ends of said s crews and means for longitudinally compressing said screws. 9;`.The,combmat1on ,with a body portion 'having ltwo alined screwthreaded openings therein, of a shaft comprising two screws lying in said'openings; a member adapted to be clamped between the ends of said screws,

tionary contact;a-contact carriedby` said r perforated,` a stapressiiw saidscrws and fixing said armature l with relation to said screws.-

10. ln a spark plug, in combination, a spool comprising a stem, an upper T-head and a lower T -head; a disk having a central l() opening and a slit connecting said opening with'the periphery of the disk, adapted to lie against the inner side of' each osaid T-heads;

a coil on said spool; a stationary contact; a

movable contact; and an armature arranged to move said movable contact.

1 1. Aspafrk pluglhaving therein'aY chamber which is open to t e pressure within the engine cylinder,l said. chamberhaving alined screw-threaded bearing openings inv its walls a movable contact, and a shaft for support- I ing said movable contact, said shaft lying in said openings andbeing screw-threaded to correspond with the screw threads in' said openings'.

' 412. A spark plug having therein a chamber which is open to the pressure within the engine cylinder, said chamber having bearing..

openings in its walls; a movable `finger carrying a contact; a shaft for supporting said finger comprising two sections extending 2 through said bearlng openings a bolt eXtending longitudinally' through said shaft-sections and clamping vthem together; a iixed contact; an electro-magnet; and an arn'iature v for rocking said shaft.

13. -In a spark plug, in combination, an electro-magnet; a shaft comprising two sec-v tions g a contact supported by said shaft; a fixed contact; an armature having two attaching arms; and a bolt extending longitw dnallythrough said shaft sections and through said arms7 and clamping said parts together,

' GEORGE J. BLUM.

Witnesses l 1 GEORGE L. CHINDAHL,

M. M. DALEY. 

